According to self-determination theory, social contexts that support students' basic psychological needs of autonomy, competence, and relatedness foster motivation toward behaviors that are valued in that social context. This study investigated the socio-contextual elements of a learning environment that support or undermine students' basic psychological needs as they relate to solving environmental problems. Individual stimulated-recall interviews were conducted with a student group after they participated in environmental problem-solving tasks over the course of a semester. Data were taken on students' reported feelings of competence, relatedness, and autonomy, and the classroom features to which they attributed those feelings. Six features of the instructional environment were inferred to be supportive of students' basic psychological needs. These are referred to as "curricular interconnectivity," "conceptualization problem sets," "instructional guidance," "socio-scientific integration" throughout the curriculum, "student-guided lecture," and "cohesive group dynamics." One feature of the instructional environment seemed to undermine students' basic psychological needs; it is referred to as the "'anything-goes' norm." These features are explained with supporting evidence and consequences regarding students' needs for competence, autonomy, and relatedness. The article concludes with a discussion of considerations when constructing science curricula, given the impacts on environmental motivation.